Fluorine (F) and tin (Sn) codoped ZnO (FTZO) nanoparticles (NPs) were synthesized by sol-gel technique on indium tin oxide (ITO). The structural changes arising from CH3NH3PbI3 deposited on FTZO NPs layer during its degradation were characterized via in situ grazing incidence X-ray diffraction (GIXRD). It was indicated that the FTZO NPs layer helped reduce the degradation of the perovskite film during the annealing process. This film also exhibited enhanced crystallization and preferred in-plane orientation of the (110) plane after annealing.